two layers of dura mater in the cranium
- meningeal layer
periosteal layer
lines inner aspect of skull
meningeal layer
- continuous with spinal dura
CSF fills
subarachnoid space
How does CSF gain access to brain and spinal cord?
What secretes CSF?
choroid plexus
What absorbs CSF?
arachnoid granulations
What are arachnoid granulations?
What is a lumbar puncture?
- needle into subarachnoid space of lumbar cistern
lumbar cistern
midline between L3-L4 or L4-L5
epidural space
space above dura mater
How do epidural anesthetics work?
Where is the gray matter of the cerebral cortex?
surface of the brain
Which spinal cord levels have a larger amount of gray matter?
those associated with limb innervation
spinal cord white matter from cranial to caudal
decreases
What are the white matter funiculi in the spinal cord?
tactile discrimination from the leg conveyed in
fasciculus gracilis
tactile discrimination from the arm conveyed in
fasciculus cuneatus
lower motor neurons
innervate skeletal muscle
lesions of lower motor neurons
fasciculation
brief contractions of muscle motor units
upper motor neurons
neurons at higher levels in the CNS that send axons either to the brainstem or spinal cord
lesions of upper motor neurons
ALS
amyotrophic lateral sclerosis